Categories let you catalog and structure the data in a simple and clear manner.
Category trees are structural units that are independent of each other, each with their own categories. You can organize these categories hierarchically, similar to the directories on your computer.
A file can be sorted into (usually) exactly one category per tree. You can thus sort this file into one category in the first tree, into a second category in the second tree, and into a third category in the third tree. Each tree represents its own catalog with its own structure.
The first category tree takes on a special position: each file must be sorted into a category of this tree, since this tree is used for the assignment of permissions.
For example, in the first tree you can illustrate your organizational structure with categories such as "management", "press", and "internal affairs". You can use a second tree for a thematic structure, and the third tree for a qualitative evaluation: "print" and "web" or the like.
You can set up as many trees as desired, with any amount of categories and nested structures.
Each tree can be set to visible or invisible.
For individual trees, except the first one, the multi-filing feature can be activated. If active, then files may be sorted into multiple categories of the tree.